(1) Field of the Invention
This invention relates to an ink jet recording apparatus which utilizes a piezo-electric body.
(2) Description of the Related Art
One conventional ink jet recording apparatus is disclosed in U.S. Pat. No. 4,819,014, in which, as shown in FIG. 1, a piezo-electric plate 51 has a plurality of elongated ink cavities each comprising two deep grooves 52 and a shallow groove 53 therebetween, a cover plate 54 being fixedly placed on the plate 51. An electrode 55 is provided on the lower surface of the plate 51. And another electrode 56 is provided on the inner surface of the bottom of the ink cavity in such a manner that it is confronted with the electrode 55 through the plate 51. A certain voltage is applied between the electrodes 55 and 56, so that ink in each ink cavity is jetted in the form of a droplet from a nozzle hole 57 as a result of its volume being varied in thickness vibration mode.
However, according to the above-mentioned construction, the distance h between the electrodes 55 and 56 must be as long as 500 .mu.m or so to sufficiently vary the volume of the ink cavity. Such a long distance demands considerably high voltage to be applied between the electrodes 55 and 56, and accordingly an expensive driver device. In addition, the piezo-electric plate 51 requires a complicated grooving thereon, which also leads to high production cost.